The New South Wales plants differ from those in Victoria in having slightly broader phyllodes with a few, obscure, impressed lateral nerves (laterals normally absent in Victoria) (Orchard and Wilson 2001). In New South Wales it may be confused with Acacia verniciflua. In Victoria it may be confused with A. leprosa. Putative hybrids between A. ausfeldii and A. paradoxa have been reported.

Justification:Acacia ausfeldii is endemic to Australia with a disjunct distribution between New South Wales and Victoria. The overall extent of occurrence (EOO) exceeds the threshold for a threatened category but the species is listed as Vulnerable in both states separately since in either state its distribution is highly restricted (EOO in New South Wales is 2,300-2,600 km² whilst in Victoria it is ~5,200 km²). The habitat for this species has been significantly reduced since settlement and it is currently severely fragmented and in decline. The populations of this species are threatened by increased salinity, changes in fire regimes, weed invasion, grazing pressure and increase fragmentation and loss of habitat. It is therefore listed as Near Threatened as it almost qualifies for listing as threatened under criteria B1ab(iii).

Acacia ausfeldii is endemic to Australia with a disjunct distribution occurring in the Dubbo-Cassilis-Mudgee area in New South Wales and the Inglewood-Nagambie area north to Torrumbarry in Victoria (Orchard and Wilson 2001). The population in Inglewood found in 1975 has not been since relocated (Orscheg 2006). The reported extent of occurrence (EOO) within New South Wales it is approximately 2,300 to 2,600 km2 (NSW Scientific Committee 2005) whilst in Victoria the EOO of the available collections is ~5,200 km2, excluding the collection in the Inglewood area.

In New South Wales the total population size is thought to be 20,000 individuals, although it is not known how many of these are mature individuals; but of the total 11-14 locations a small number of locations (6-8) contain 90% of the total population (NSW Scientific Committee 2005). The number of known extant populations in Victoria was 39 in 2003, with only nine populations exceeding 1,000 individuals (Brown et al. 2003).

A shrub or tree 2-4 m high that grows in eucalypt woodland in sandy soil often in remnant roadside patches of woodland in New South Wales, while in Victoria it grows in dry forest and mallee communities, generally restricted to box-ironbark (Eucalyptus microcarpa - E. tricarpa) open forest. A. ausfeldii is likely to have a dormant soil seedbank from which germination is stimulated by fire and established plants are likely to be killed by fire, as mature and juvenile plants have a single-stemmed growth form and there is no evidence of fire-resistant organs.

In New South Wales most of the native habitat where this species occurs has been cleared for agriculture and substantial habitat loss for this species has occurred since settlement of the region. Half of the remaining populations are located within an agricultural landscape on road verges, whilst other occurs in pastoral land. The main threats identified are: roadside disturbance with half of the remaining populations located within an agricultural landscape on road verges; weed invasion, grazing and small-scale clearing resulting in population decline and population viability within conservation reserves, state forests and leasehold lands may be affected by adverse grazing regimes or adverse fire regimes. The largest populations located in conservation reserves are less likely to decline unless their viability is affected by adverse grazing or fire regimes (NSW Scientific Committee 2005). In Victoria this species is listed as "at Risk" in the Victoria Riverina and Victorian Midlands subregions with the main threatening processes being increased salinity, changes in fire regimes, weed invasion, grazing pressure and increase fragmentation and loss of habitat (Australian Natural Resources Atlas 2009).

Known to occur within the Yarrobil National Park and Munghorn Gap Nature Reserve in New South Wales; and the Greater Bendigo National Park in Victoria. The species has been listed as Vulnerable in New South Wales as it is facing high risk of extinction in the medium term (NSW Scientific Committee 2005) and also listed as Vulnerable in Victoria (Department of Sustainability and Environment 2005), however, it is not listed as threatened under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act). The seeds for this species have been collected as part of the Millennium Seed Bank project. Seeds are located at: Mount Annan Botanic Garden, New South Wales (Australia) and Wakehurst Place, Royal Botanic Gardens, Kew (UK).

Department of Sustainability and Environment. 2005. Advisory List of Rare or Threatened Plants in Victoria - 2005. In: Department of Sustainability and Environment (eds). Department of Sustainability and Environment, East Melbourne.

Orscheg, C. 2006. Completion report to the Australian Flora Foundation. Seed longevity and viability in several plant species of Box-Ironbark Forests. School of Anthropology, Geography and Environmental Studies, Parkville.